35 ford running bad-need suggestions

[bullrunmotor]

Been running a 35 pickup-21 stud- with dual intake (old edmunds)and 2 97's for 10 years with no problems. Started missing, running rough, rough idle-no power i have done the following:


Totally rebuilt distributor-timing set on fixture and coil rebuilt by skip.


Removed heads-checked all valve clearances-pulled all out-checked guides and inspected springs. Lapped all valves. A couple of valves were tight-no bad seats or valves. Good compression across all 8


all new plugs-wires are fairly new. Fuel pump is fairly new pumps like crazy when tested. I'm leaning towards carbs now.


Carbs had been rebuilt about a year ago. Don't think they are an issue. I'm thinking about fabricating a blank off plate and trying to run one carb at a time and see if i determine it runs well with one carb and not the other . Any of you got any ideas on that? I imagine i could also replace 2 pot set up with single intake set up and see if it runs well again. Truck ran so well for 10 years. Can't figure it out. Can a ballast go flaky and have an effect on ignition. Possible a vac. Leak? Any suggestions appreciated. Thanks in advance

[tubman]

Things to check : condenser, ignition switch and voltage at coil. I had a '36 and started having problems and it turned out to be the ignition switch had gotten corroded inside. I'd try these before I started doing any serious messing with the carbs.

[Mike in AZ]

What do the plugs look like? Black? Sooty? Etc. How new is fairly new fuel pump? Could be too much pressure Mike

[bullrunmotor]

Good point on possible voltage loss. Coil/condenser/fuel pump etc aren't the problem as we've swapped out multiple units. Can anyone confirm we should have 6V going to the resistor and 3v exiting the resistor towards the coil. Thanks

[Viv W]

Sounds like a faulty condenser to me. Don't be fooled into thinking that new condensers are all good. I bought 6 new ones for my Model A and they were ALL faulty.

[50fordcoupeman]

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Agree with Viv. I had 4 new coils and they were all bad. Can make you go crazy!!

[JSeery]

Originally Posted by bullrunmotor

Can anyone confirm we should have 6V going to the resistor and 3v exiting the resistor towards the coil. Thanks

Something in that range.

[koates]

Originally Posted by bullrunmotor

Good point on possible voltage loss. Coil/condenser/fuel pump etc aren't the problem as we've swapped out multiple units. Can anyone confirm we should have 6V going to the resistor and 3v exiting the resistor towards the coil. Thanks

You will only get those voltage readings provided the timing contacts in the distributer are closed. If the points are open then you will get 6 volts at the coil also. Regards, Kevin.

[Tinker]

Originally Posted by koates

You will only get those voltage readings provided the timing contacts in the distributer are closed. If the points are open then you will get 6 volts at the coil also. Regards, Kevin.

At coil 3, closer to 4v is better.

Koates, Please explain more?




.

[Brian]

I had a problem with my 35, running real ragged etc. I was convinced it was electrical; condenser or similar. I changed out distributors, condensers etc for months to no avail....finally, thought "I wonder if the heat riser in the [twin carb] intake has blown out?"...removed intake and plugged the heatriser holes each side. Viola!! a beautiful thing once again!!
Try the obvious things, if they don't make any improvement, try plugging those heat riser holes.

[Tinker]

I've plugged my intake crossover risers when I lived in florida. Made a difference in carburetor heat.

Still have them in, now in mn. (I only drive when it's warm, above 40 degrees (and the salt is gone))

I guess back in the day you needed that heat to warm up a carburetor in the cold, quickly. Then... when you only drove that vehicle as a family car (only). To most, it is fairly impractical and adds heat to an area that doesn't need it. I just used a couple sheetmetal shims.

Racers have been pluggin them for ever.



My opinion anyway.




.

[cas3]

brian, when those burn thru, can it be seen, or is it up inside, and how to test as i have an aluminum 35ish manifold i'd like to use on my 59a

[Tinker]

Try a new condenser. IH200

[koates]

[QUOTE=Tinker;1730745]At coil 3, closer to 4v is better.

Koates, Please explain more?
Tinker, The timing contacts in the distributer need to be CLOSED (not OPEN) to energise the coil circuit to ground and create a load on the resistor which causes a voltage drop across the resistor. The flathead V8 coil is designed to operate on 4.5 volts powered through the resistor. Tinker I thought you knew how all this stuff worked !! Regards, Kevin.

[Tinker]

[QUOTE=koates;1730773]

Originally Posted by Tinker

At coil 3, closer to 4v is better.

Koates, Please explain more?
Tinker, The timing contacts in the distributer need to be CLOSED (not OPEN) to energise the coil circuit to ground and create a load on the resistor which causes a voltage drop across the resistor. The flathead V8 coil is designed to operate on 4.5 volts powered through the resistor. Tinker I thought you knew how all this stuff worked !! Regards, Kevin.

Originally Posted by koates
You will only get those voltage readings provided the timing contacts in the distributer are closed. If the points are open then you will get 6 volts at the coil also. Regards, Kevin.


Thought we were talking about voltage at coil. How does it make 6 volts if the power feed is 4volts or lower? and how does the voltage get pasted the resistor?


I only know enough to get me into trouble.

[JSeery]

Koates has it. Points closed, 6+ on the ignition side of the ballast resistor and 4 to 4 1/2 on the coil side. (I should not have answered so quickly earlier!)

[Tinker]

Please explain why?


On the ignition main harness power feed/power side of a resistor (before the resistor) is always 6v. Even if the points are closed or open. 4v +/- at coil.


I'm serious, please explain.

[jetmek]

I had a similar issue a few years ago drove me crazy for months long story short it had a bad power valve in one of the strombergs acted just like an ignition problem

[Tinker]

Originally Posted by jetmek

I had a similar issue a few years ago drove me crazy for months long story short it had a bad power valve in one of the strombergs acted just like an ignition problem

Stromberg 97s don't have power/pressure valves.

[jetmek]

Originally Posted by Tinker

Stromberg 97s don't have power/pressure valves.

UMM yes they certainly do. at the bottom of the accelerator pump well.